2003 Ford Taurus losing acceleration when hot

[Drooopy33]

Ok so I've taken a break from the Taurus as it was driving me nuts lol. So I'm back at it, though I am yet to change the MAF (my next step today) I noticed something I had not before. The car seems to be running fine in the park position, I can rev up to high RPM's and nothing unusual. Soon as the car is out into drive it starts to bog and can't give any gas without it wanting to stall. Once I put the car back into park it will catch itself and I can again rev it up. Any ideas?? Or do you think this could be the MAF doing this?? Ps, all O2 sensors have been changed and so far no lights on dash.

[shorod]

It sounds like the car only has issues when under a load. That could be a lot of things, and without the diagnostic equipment to see what's happening, you're kind of stuck shot-gunning parts and hoping you get lucky.

Normally I'd say it's probably spark plugs or plug wires, but you stated you previously replaced those. Of note though is you said after that it might have even gotten a little worse. Maybe one of the spark plug wires is not making a good connection?

A MAF that doesn't read correctly could cause an issue under load, but again without having datastream data for the MAF, it's just a guess. Fuel pressure could be another cause, but I think you previously said you changed the fuel pump and fuel filter as well, so that reduces the chances that's the issue.

Maybe you have an intake air tube with a crack in one of the accordion folds that opens when the engine shifts under load. Worth checking. Or maybe there is a brittle vacuum line or mis-routed vacuum hose that opens or gets pinched when the engine shifts.

-Rod

[Drooopy33]

Ok I'll see what I can do and start checking things off hoping I get lucky. But yes definitely seems to be only when it's under load. Thank you again. I'll let you know what I come up with if anything. If you think of anything else I'd greatly appreciate the information. Thanks again!

[Drooopy33]

Just for those who have read this post that may have had a similar problem. I never did find out the issue. I believe the transmission just was breaking down so I ended up selling the car.